(Yes, I am aware of the irony on installing yet another plugin to solve the problem!)

Following the steps of PluginHogDetector will significantly decrease the amount of time you’ll have to take in order to find the offensive plugin.

In the end, you could also save significant money with this free plugin as your hosting company will not have a reason to harrass you to upgrade your hostng plan or risk having a blank site until the next bandwidth reset.

Or, (fingers crossed for us both), you could determine that the cause is not plugins but a significant amount of traffic.